Electric switch



.July 14, 1936 v I G. R. BROWNV 2,047,931

ELECTRIC swIvT'cH Filed Nov. l5, 1935 58 Fig. 7. "4

I ,Fig 5- 46 62. 4l as Inventor:

George R. Brown, f

Patented July 14, 1936 UNITED. STATES ELECTRIC SWITCH George Bf. Brown,Stratford, Conn., assignor to General Electric Company, a corporation ofNew York Application November 15, 1935, Serial No. 49,943 e claims. (ci.zoo-152) The present invention relates to electric switches of the typehaving liquid contact circuit closers for controlling the ow of current.

'I'he object of my invention is to provide an improved construction andarrangement in switches of this type and for a consideration of what Ibelieve to be novel and my invention attention is directed to theaccompanying description and-the claims appended thereto.

In the accompanying drawing, Fig. 1 is a sectional sideelevation of aswitch embodying my invention; Fig. 2 is a bottom plan .view partlybroken away of the switch shown in Fig. 1; Fig. 3 is a sectional viewtaken Von line 3 3 of Fig. 1; Fig. 4 is a sectional side elevation of amodication of my invention; Fig. 5 is a bottom plan view partly brokenaway of the switch shown in Fig. 4; Fig.` 6 is a sectional view taken online 6 6 of Fig. 4; and Fig. 7 is a view showing the construction andoperation of the liquid contact circuit closer. d

Referring to the drawing, I have illustrated my invention using a liquidcontact circuit closer having a pair of cup-shaped metal terminals Iwhich are separated by an insulating diaphragm 2 of a refractorymaterial, such as a ceramic material. The edges of the terminals aresealed by a bead '3 of glass which also seals the junctions between thediaphragm and the terminals. Within the space enclosed by the terminalsis a suitable quantity of mercury 4 which forms the conducting mediumbetween the terminals. In the manufacture of the circuit closer thespace enclosed by the terminals is evacuated and lled with hydrogen at apressure of one or more atmospheres which increases the currentinterrupting capacity of the circuit closer. As shown by the Vfull linesin Fig. 7, the diaphragm 2 is provided with an opening 5 which is`submerged in the mercury when the circuit closer is in thecurrent-conducting position. `When the circuit closer is in thecurrent-interrupting position shownin dotted lines in Fig. 7, theopening 5 is above the mercury, and the circuitbetween the terminals istherefore broken by the insulating diaphragm 2. Due to the constructionof the circuit closer, the interrupting of the circuit between theterminals takes place in the mercury as the circuit closer is turned sothat the opening 5 in the diaphragm approaches the dotted line position.The above described construction is illustrative of liquidl contactcircuit closers which are suitable for use in a switch embodying myinvention.

t The switch in Figs, 1 to 3 inclusive has a frame which comprises twolongitudinal tracks 5 riveted at one end to a piece of insulatingmaterial I and having iianges 8 at the other end riveted to inserts 9held in a block I 0 of insulating material. Above the tracks 6 is ametal strip II having a ange I2 secured to the block I 0 by a rivet I3and having a ange I4 at the other end provided with a tongue I5 whichflts into the strip 1. Between the strip 1 and the strip II is a braceIB having a 'ange I1 riveted to the strip I I and having a tongue I9tting in the strip 1. The brace I6 holds the strip I I in spacedrelation to the tracks 6 and secures these parts in assembled relation.

'I'he inserts 9 which are riveted into the block i0 have terminal screws20 threaded therein to -which the line conductors may be attached. Theblock I0 is provided with a projection 2| which provides an insulatingbarrier between the terminals 20. To the inner end of each of theinserts 9 is secured one end of a spring contact strip 22. The springstrips 22 rest on the upper surface of the tracks 6 and extend aroundthe periphery of the terminals I of the liquid contact circuit closer.

The other end of each of the strips 22 extends terminals 20 to theterminals I of the circuit closer. The strips 22 are iiexible enough sothat as the circuit closer is rolled along the tracks 6, the contactstrips are wrapped around the periphery of the terminals. 'I'he strips22 are stii enough so that they tend to move the circuit closer to theleft, as viewed in Fig. 1.

Slidably mounted in the brace I6 is a plunger 24 having a hollow cup 25secured t`o its lefthand end. 'I'he cup 25 is slidable in the ilange I 4of the strip II, and a helical spring 26 arranged between the brace I6and the bottom of the cup biases the plunger to the left, as viewed inFig. l. 'I'he right-hand end of the plunger 24 is riveted to a block orcarriage 21. The

strips 22 on the periphery of the terminals I.

When the plunger 25 is pushed to the right, as

viewed in Fig. 1, the circuit closer is rolled on .fthetracks 6,Wrapping the contact strips 221 around-the periphery of the terminalsand thereby causing rotation of the circuit closer about its axis. Whenthe plunger 25 is moved to the left under the action of spring 26, theresilience of the contact strips 22 causes the circuit closer to roll tothe left, keeping the terminals I against the curved surfaces 3| of thecarriage. The bead 3 of the circuit closer extends between the tracks 6so that it serves tov maintain the circuit closer on the tracks duringthe rolling movement.

The switch is assembled within a cylindrical housing 32 having a splitcoupling 33 at one end for clamping to a conduit containing the lineconductors. At the other end of the housing 32 is a ange 34 to which issecured a cover plate 35. A tongue 36 on the flange I4 fits within acomplementary depression 31 in the flange 34 and locates the switchwithin the housing 32. A sleeve 38 of insulating material is placedbetween the 'housing and the switch. Y

One use of the switch is as a door switch to control an electriccircuitv in response to` the opening and closing of a door. In this use,the switch is mounted in the door jamb by means of the cover plate 35,and the line conductors are connected to the terminals 20. Opening andclosing of the door will then cause reciprocation of the plunger 24 andthereby cause rotation of the circuit closer about its axis.

In the modification shown in Figs. 4 to 6, inclusive, the switch has aframe which comprises a pair of spaced tracks 39 having flanges 40 atone end secured to a block 4I of insulating material and having anges 42at the other end secured to a block 43 of insulating material by sleevenuts 44. The threaded sleeve 44 andthe binding screws 44a serve'as lineterminals for conductors which extend through openings,45 in the block4I and similar openings in the block 43. The sleeves 44 extend throughthe block 43, and the inner end of each is secured to one end of aspring contact strip 46. The spring contact strips 5 46 rest on theupper surface of the tracks 39 and carries a block 52 of insulatingmaterial.

rolled to the left, as viewed in Fig. 4, the strips i will be wound o nthe periphery of the terminals, but are sti enough so that they tend toroll the circuit closer to the right.

For moving the liquid contact circuit closer, 'I have provided a plunger49 which is slidable ln a. bearing 50 in the block 43. The right-handend of the plunger is fixed to a carriage 5I which The block 52 fitsover the bead 3 of the circuit closer and is provided with a curvedsurface 53 which slidably engages portions of the strips 46 on theterminals I. The plunger 49 is biased to the left,

aS vieWed in Fig. 4, by a coil spring 54 which is carried in a recess 55in the block 4I. Atongue 56 on the carriage centers the spring withrespect to the carriage.

The switch is enclosed by a cylindrical housing 51 having a splitcoupling 58 at one end for clamp-i ing a conduit containing the lineconductors. At the other end of the housing 51 is va ilange 58-a towhich` is secured a cover plate 59. The switch is held within thehousing by an insulating sleeve 60 arranged between the cover plate 59and the left-hand face of the block 4I.. The sleeve 60 forces theright-hand face of the block 4I against projections 6I struck up on theinner surface of the housing 51. In Figs. 4 and 5, the switch is shownin the position in which the plunger 49 has been pushed to the right. Inthis position, the contact strips 46 hold the terminals of the liquidcontact circuitl closer against the curved surface 53 ci the block 52.When the plunger 49 is released, Vthe spring 54 forces the carriage 5Ito the left thereby causing the circuit closer to roll to the left onthe tracks 39. 'Ihe rolling of cuit closer operable by rotation aboutits axis, said 25 circuit closer having a curved portion on itsperiphery, a track on which said curved portion is adapted to roll, andmeans for rolling said circuit closer on said track.

2.V In an electric switch, a. liquid contact circuit 30 closer operableby rotation about its axis, said circuit closer having a curved portionon its periphery, atrack on which said curved portion is adapted toroll, and a carriage slidably engaging the periphery of said circuitcloser for rolling said 35 circuit closer on saidtrack.

3. In an electric switch, a liquid contact circuit closer operable byrotation about its axis, said circuit closer having a curved portion onits periphery, a track on which said curved portion is 40 adapted toroll, a spring strip fastened to said circuit closer and having atendency to roll said f circuit closer in one direction, and means forrolling said circuit closer on said track in opposition to the force ofsaid spring strip.

' 4. In an electric switch, a liquid contact circuit closer operable byrotation about its axis, said cir` cuit closer having a curved portionon its periphery, a track on which said curved portion is adapted toroll, a spring strip fastened to said circuit 50 closer and having atendency to roll said circuit closer in one direction, and a carriageslidably engaging the periphery of said circuit closer for rolling saidcircuit closer on said track in opposition to the force of said springstrip.

5. In an electric switch, a frame having a pair of spaced tracks, aliquid contact circuit closer operable by rotation about its axis, saidcircuit closer having portions adapted to roll on said tracks, and aportion extending between said 60 tracks for holding the circuit closeron the tracks,

' and means for rolling said circuit closer on said track.

6. In an electric switch, a frame having a pair of'spaced tracks, aliquidv contact circuit closer 65 operable by rotation about its axis,said circuit closer having portions adapted to roll on said tracks and aportion extending between said tracks for holding the circuit closer onthe tracks,

and means including a plunger slidable in said 7o frame for rolling saidcircuit closer on said track.

7. In an electric switch, a liquid contactcircuit closer operablebyrotation aboutits axis, a resilient strip secured to and wrapped aroundthe periphery of said circuit closer, and means for 75 rolling saidcircuit closer on said strip for causing rotation of the circuit closerabout its axis.

8. In an electric switch, a liquid contact circuit closer operable byrotationabout its axis and having a cylindrical terminal, a spring striphaving one end wrapped around the periphery of the terminal and heldthereon by the resilience of the strip, said strip and said terminalhaving intertting portions for preventing slippage between the strip andthe terminal, and means for rolling said terminal on said strip forcausing rotation of the circuit closer about its axis.

9. In an electric switch, a frame having a pair said circuit 10

